The present invention relates generally to a device for detecting air flow through a passageway and, more particularly, to such a device which detects the presence of air flow, as well as the direction and magnitude of air flow through such a passageway.
The present invention, in one embodiment, is suitable for use in an inhalation device for the delivery of fluid or medication to a user. Small hand-held inhalation devices are widely used for dispensing or administering prescribed dosages of aerosol-type medication, particularly for persons having breathing disorders, such as asthma or the like. Such dispensing devices generally comprise a plastic, generally tubular housing which is generally L-shaped in cross section. One end of the housing is adapted for receiving an aerosol container or module which contains the medication, as well as some form of propellant. The other end of the housing includes a mouthpiece which is adapted to be inserted into the mouth of the user. The housing also includes some type of actuating device which causes the medication to be released from the aerosol module for inhalation by the user. Typically, release of the medication requires that the module be moved inwardly with respect to the housing for release of the medication.
As previously indicated, inhalation devices of the type described above are widely used for the delivery of such medication. However, many persons are unable to successfully utilize such devices. Devices of this type generally require that the aerosol module be moved with respect to the housing to release the medication into the housing essentially simultaneously with or immediately followed by inhalation to obtain the full benefit of the medication. Many patients, because of infirmities, age or the like are unable to successfully perform such a two-step process, either simultaneously or in rapid succession. Consequently, such persons either cannot utilize such inhalation devices at all or, in some cases, obtain only a partial benefit from the medication.
The present invention is employed as part of an automatic inhalation device which requires only a single action on the part of the user: inhalation. Means are provided for detecting inhalation by the user and for automatically actuating the aerosol module for release of a predetermined quantity or dose of the medication without any further action by the user.
In another embodiment, the present invention may be employed for monitoring the breathing of a user. For example, the present invention may be employed with a trachea tube or a mouth- or nose-inserted breathing tube for monitoring the breathing of the user. The present invention permits monitoring of the respiration rate and the depth of breath, as well as changes in the respiration rate.